多对极发电机励磁绕组匝间短路故障在线定位理论研究

Theoretical Study of On-line Location of Inter-turn Short Circuit Fault of Generator Field Windings with Multiple Poles

大型水轮发电机和抽水蓄能发电电动机均为多对极,现场迫切希望实现故障磁极的在线定位。本文基于一台3对极、12kW的发电机动模样机研究在线定位的理论基础。首先,采用场路结合法对该样机在联网工况下的励磁绕组匝间短路故障进行了计算,并与实验结果进行了对比和分析,验证了计算模型的正确性。然后,利用故障数学模型对该样机一极短路故障进行了计算,基于仿真结果,研究故障磁极、励磁磁动势、定子电动势和定子分支环流之间的相位关系。研究表明:定子分支环流的1/P次谐波相位角(P为发电机的极对数)可以用于对故障磁极的判断。本文为实现多对极大型发电机励磁绕组匝间短路故障的在线定位奠定了理论基础。

Large hydro-generator and generator-motor have multiple magnetic poles,so it is urgent to realize on-line location of fault pole in engineering.In this paper,based on a 3-pole,12kW generator,the theoretical basis of on-line location is analyzed.Firstly,the field circuit combination method is used to calculate the inter-turn short circuit fault of the field windings.The calculation results are compared with the experimental results,and the correctness of the calculation model is verified.Then,the fault mathematical model is used to calculate the fault of one pole short-circuit of the generator.Based on the simulation results,the phase relationship among fault pole,excitation magnetomotive force,stator electromotive force and stator branch circulating current is analyzed.The results show that the 1/P harmonic phase angle of stator branch circulating current can be used to judge the fault pole(P is pole pairs of motor).This paper lays a theoretical foundation for on-line location of inter-turn short circuit fault of generator field windings with multiple poles.